Folding ladder



P. ZEMAN FOLDING LADD 2 SheetSrS 1 Filed May 8. 1956 Q -ix .g

INVENTOR ATTORNEY Aug. 23, 1938. R E N 2,127,949

- I FOLDING LADDER Filed May s. 1936 2 Sheets-Sheet 2 ll INVENTQR 9/ATTORNEY Patented Au 23, 1938 UNITED STATES PATENT OFFICE FOLDING LADDERPaul Zeman, New York, N. Y. Application May 8, 1936, Serial No. 78,556

7 Claims.

My invention relates to improvements in folding and extensible stepladders, and has for its object, to provide a new and improved foldableand extensible step ladder.

This is an improvement upon the Folding ladders as shown and claimed inLetters Patent of the United States, Number 2,021,494, granted onNovember 19, 1935, to the inventor hereof, Paul Zeman.

The object of my invention is to provide a folding step ladder that ifof strong, durable and cheap construction, and with a large factor ofsafety, light in weight, simple, fast, and easy to operate, and whichtakes very small space to transport or store.

A further object is to provide an extensible and foldable ladder of Ashape, with steps either on both sides, or only on one side, in whichevent, the other side constitutes a brace or a prop.

A further object is to provide several different lengths of a ladderthat may be a combination of two or more folding ladders, all of whichcan be extended or collapsed, individually or as one structure. 3

A further object is to provide an extensible and foldable ladder of Ashape with both supports adaptable for collapsing, and adjustable inoperative position, on any irregular support or surface, each side ofthe ladder being on a difierent plane,

as needed on Stairways.

construction. The side frames box form.

are preferably of In the drawings, accompanying this specification andforming part of this application, I have illustrated one practical formof the invention which at the present time, may be regarded as thepreferred form, in which drawings:

Figure l is a front elevation of the ladder made in accordance with myinvention showing the side frames and the steps in collapsed position,and the single locking means for releasing the ladder from its operativeposition to its collapsed .position, ready for storage ortransportation.

Figure 2 is a side elevation of the apparatus, as shown in Figure 1,showing the front and rear side frames of the ladder gether,

Figure 3 is a sectional view taken about the plane 3-3 of Figure 1,looking in the direction of the arrows at 3--3, showing thecross-section of the side frames when collapsed.

Figure 4 is a sectional view taken at about the plane 4-4 as shown inFigure 1, looking in the direction of the arrows at 4--4showing thesingle releasing means.

Figure 5 is a side elevation of the ladder showing the front and rearside frames extended, and drawn out at a desired angle to represent thestep ladder braced in its operative position.

Figure 6 is an enlarged fragmentary sectional elevation of the laddershowing a pair of the bottom sections, and a pair of the intermediatesections of the side frames of the ladder drawn to-' gether, but nottelescoped into folded position.

Figure 7 is a sectional side elevation taken at about the plane l-l, asindicated in Figure 3, looking in the direction of the arrows, showingthe telescoped position of the sections when the ladder is folded.

The ladder, in the form illustrated, comprises front side frames 8, andrear side frames '9, joined together at the top by means of a platformit.

Each of the front and rear side frames, 8 and 9, is shown as made up ofa number of telescopic sections, and at the bottom provided with restingfeet or caps, or shoes i i which may be composed of rubber or othersuitable material adapted to fix the ladder in an operative position, orwhen stored, to protect the surface on which the ladder is standing, andto prevent the ladder from slipping.

The number of telescoping sections is such as to provide the desiredlength of the ladder for use.

In the form illustrated, there are shown six of such sections,designated by the reference characters, i2, it, it, it, it, and if,respectively, each of which comprises a side standard on each side,joined together by a step, it, i9, 2t, 2!, and 22, at its top, exceptthe top section H, which is joined to the platform it. The lowestsection ii, of the side frames 8, and 9, and the first steps l8,are'stationary. The side standards of each section telescope with thecorresponding standards of the adjacent sections, as will be understoodAll the telescopic sections are of the same general construction,each'one being large enough to provide for the telescoping of nearly thefull length of the sections above. Means are provided for automaticallylocking eachtelescoping section when-extended in an operative position,and

for automatically releasing them by a common releasing means in order toperform the telescoping operation of the ladder. Specifically, I havearranged that by manual releasing of one of the telescoping sections, oneach front and rear side frame and collapsing of same, the adjacenttelescoping section will thereby be released and collapsed automaticallyin one continuous motion.

In the specific form illustrated, telescoping sections l3, l4, I5, l9,and I1, are provided with aset of double action spring controlledholding dogs 23, which are concealed in a housing 24, formed at thebottom of the telescoping section.

Each set of holding dogs on each of the telescoping sections consist oftwo pins 25, formed in such a manner that one end is round pointed, andthe other end is provided with a head, both of which'pins are pressedwith the head in opposite direction against a spring 29. These pins arelong enough, that in the normal operative position, they will protrudecorrespondingly through orifices 21, provided for same in the nextadjacent telescoping section to hold same in an operative position.

The upper part of each telescoping section l2, l3, l4, l5, and I6,except the one adjacent to the platform ID, has a box form provided witha cam 28, on both its sides so that as each telescoping sectioncollapses, the cam travels over the round pointed form of the doubleaction spring controlled holding'dogs of the next adjacent section,pressing the same inwardly far enough to permit the holding dogs to bereleased from the orifices of the next adjacent section to I telescopethe ladder into a folded position.

Extending the ladder, from the folded position into the operativeposition requires drawing out the telescoping sections l3, I4, I 5, l6,and i1, until the holding dogs 23, of each separate section, registerwith the respective orifice 21, of the adjacent sections. Thetelescoping sections l2, l3, l4, l5, and I6, are also provided withmeans to prevent dislocation of the sections, and to further fix them inthe operative position. In the illustrations, I have specificallyprovided the lower part of the respective sections with a rivet 29,which is located immediately above the housing 24, of each section. Thisrivet moves in a guiding slot 39, .of the adjacent section, and acts asa stop to assure the proper register of the holding dogs 23, into theorifice 21, when the rivet 29, engages the end of the guiding slot 39.

In order to secure uniform and proper unfolding of each set of opposingsteps, [9, 20, 2i, and 22, means are provided for coordination betweeneach set. I have shown by reference character 3|, one of such means,comprising a pin 3|, on one side of the step and groove (3Ia) on therespective opposing step, through which they are associated whileunfolding is being performed.

The releasing mechanism for the holding dogs 23, as represented in theillustration, comprises special box sleeves 32, which are slidinglymounted at the top of each telescoping section l2. They are arranged topermit the simultaneous release of the holding dogs of the four lowesttelescoping sections l2, when the apparatus is to be folded.

The box sleeves 32, are provided with a cam 33, on each side which is sodesigned that it is free from the holding dogs when the ladder isextended or in an operative position, but so that when the sleeve isdepressed, it will press the pin 25, inside the side frame'to releaseit; whereupon 75 the next adjacent section collapses followed bysections l4, ll, l9, and I1, each following the other as its holding dogis in turn released, thus folding the ladder into its collapsedposition.

The bottom surface of the lowest step ll, upon which is provided asocket 34, into which is mounted a bolt 33, projecting downwardly,passing through bracket 39, which is firmly connected on one side with abox sleeve 32; and a spring 31, surrounding the bolt. presses upwardlyupon the bracket 36, to hold the sleeve in its raised position. Thisbracket also carries an eye 33.

A wire 39, has two branches pivoted together, each having two arms andis diagonally arranged and connected to the four eyes 38, so that itconnects and operates all four sleeve portions 32, simultaneously. Atthe central point is a foot pedal 40, for operation of the wire 39.

Two front side frames 8, and two rear side frames 9, are rigidlyconnected and fixed by a bar 4|, between the lowest telescoping sectionsI2, provided by a locking device 42, adjacent to the side frames inorder to keep them together when the ladder is being telescoped andcarried in a folded position. This bar also provides for an additionalbracing, giving rigidity to the ladder in the operative position.

A further bracing and rigidity of the ladder is, provided for by meansof the wire 39, to take care of the forces in tension, and by two hingedrods 43, connecting the two sides of the corresponding pair of front andrear side frames at such relative space and distance above the wire 39,to take care of the forces in compression or thrust, and also to fix thedesired angle of the ladder in operative position. Each hinged rod 43,is held extended by a spring locking device and may be released bypulling a pin 44, in the middle, between each pair of the hinges 43, soas to allow the hinge rods to be folded or extended, as may be requiredwhen the ladder is to be folded or fixed in an operative position.

When the ladder is in a collapsed and folded position, it is secured insuch a position by the locking device or means, one of the forms beingas illustrated by a strap 45. attached to the platform i9, and buckle48, attached to the lowest step l9, making it ready for transportation.

Other changes may be made within the scope of the appended claimswithoutdeparting from the spirit of the invention, and I do not, therefore,limit myself to the particular construction shown.

Having thus described my invention, I claim and desire to secure byLetters Patent:

1. In a collapsible and extensible ladder in combination, a series ofpairs of telescoping sections, with steps mounted thereon, a lockingmeans, carried by each of the telescoping sections to lock it in anextended position byengaging the adjacent section, manually operablereleasing means for releasing one of said locking means, and meanscarried by each section for releasing the locking means of the adjacentsection.

2. In a collapsible and extensible ladder in combination, a series ofpairs of telescoping sections, with steps mounted thereon, a springholding dog carried by the lower end of each of the telescoping sectionsin such a position to engage the adjacent section when the sections arein an extended position, a cam carried by each of said sectionsoperative on collapse of said section for releasing the locking actionof the holding dog of the adjacent section, and manual means for theholding dogs i'rames, and connecting the said lowermost sectionstogetherl thrust members. connecting intermediate sections ct said frontand rear side frames; said thrust members and said releasing means oisuch relative length, and at such relative distance apart, that saidthrust members are in compression, and said releasing-means bracing theaction of the telescoping sections from sagging inwardly toward eachother.

4., In a collapsible and extensible ladder in combination, a seriesoi'pairs of telescoping sections with steps mounted thereon, a lockingmeans carried by each of said sections to lock it in an extendedposition by engaging the 'ad- I Jacent member; a box sleeve in such aproportion to flt around and be associated with the upper part of eachof the bottom telescoping sections of the frame, provided with a cam,and means also associated with each of the bottom sections by which allof the said box sleeves may be operated simultaneously, therebysimultaneously releasing all the lowest holding dogs, and means uponeach upper section for releasing the locking means of the next adjacentsection above when said upper section is collapsed thereby.

5. In a collapsible ladder in combination, a series of pairs oftelescoping sections, a step rigidly connecting the members 01- eachpair, a

withdraw the same.

locking means carried by the bottom of each step of said sections toengage a recess in the next adjacent section below when said sectionsare in extended position and a treadle situated below said lowermoststep connected to withdraw the locking mechanism of the next adjacentstep above to permit collapse of the same when said treadle isdepressed.

6. In a collapsible ladder in combination, a seriesoi' pairs 01'telescoping sections, a step rigidly connecting the members of eachpair, a locking means carried by the bottom oi each step of saidsections to engage a recess in the next adjacent sections below whensaid sections are in extended position and a treadle situated below saidlowermost step connected to withdraw the locking mechanism 01' the nextadjacent step above to permit collapse of the same when said treadle isdepressed, said ladder being-arranged whereby on depression oi saidtreadle said ladder may be completely collapsed.

7. In a collapsible ladder in combination, a series of pairs 01telescoping sections, a step rigidly connecting the members of eachpair, a locking means carried by the bottom of each step of saidsections to engage a recess in the next adjacent section below when saidsections ,are in extended position and a treadle situated be- PAULzEMAN.

